Telephone system



H. P. CLAUSEN AND C. L. GOODRUM.

TELEPHONE SYSTEM. APPLICATION FILED JULY r4,1917.

1,407,985, Patented F611. 28, 1922.

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flan/y C/ausen Char/es L. Good/um W 4/7 UNITED STATES PATENT OFFICE.

HENRY P. CLAUSEN, OF MOUNT VERNON, AND CHARLES L. GOODRUM, 0F NEWYORK,

N. Y., ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Application filed July 14,

To all whom it may concern Be it known that we, HENRY P. CLAUSEN and CHARLES L. GooDRUM, citizens of the United States, residing at Mount Vernon, in the county of l Vestchester and State of New York, and at New York, in the county of New York and State of New York, respectively, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone systems, and more particularly to subscribercontrolled machine switching systems, the object, in this instance, being to provide a type of selective switch in which a double selection may be made through one-setting of calling device.

A feature of the present invention is a means responsive to the manner of setting a calling device, whereby a selection is made which is independent of that made in response to the position in which the calling device is set. According to this feature, a dial switch is provided which may be rotated in either a clockwise or a counter-clockwise direction, which, when and while being rotated in one direction, will cause an impulse to be transmitted to accomplish an additional selection in a seized selector switch.

In most well-known types of selective switches, current is supplied to the line, which has seized the switch, through a socalled line relay which then becomes responsive to the' rapid opening and closing of the line circuit through a calling device at the substation. In addition, there is provided in the present instance a differentially wound relay through the windings of which this line current is caused to travel. Being difierentially wound, this relay is unresponsive to such current. However, if the balance of the line is disturbed, it becomes responsive. The dial switch is therefore so arranged that while being set through rotation in one direction, the balance of the line will be temporarily disturbed, upon which the beforementioned relay responds, locks itself in its actuated position and causes thereby an additional selection in the selective switch. I

It is thought the invention may best be understood by reference to the accompanying drawing, in which a calling substation, a line Specification of Letters Patent.

1917. Serial a... 180,609.

finder switch, a connector "switch, and two called substations have been diagrammatically represented.

An idea of the general construction of a d al switch adapted to rotate in either direction may be had from the patent to H. P. Clausen, No.1,337,198, issued April 20, 1920.

The dial switch used in the present arrangement is shown in association with the subscribers station S It consists essentially of the dial D, a set of impulse springs C, a finger stop S, and an associated contact 1, which is operated only during the setting of the dial and while the dial is being rotated in a clockwise direction.

lVhen the subscriber at S removes his receiver from its hook, the line finder switch LF is actuated to extend the line to the selector switch SS in a manner well-known to one skilled in the art... A circuit is thereupon established from ground, the right-hand winding of line relay LR, the right-hand winding of relay 2, the first position contact and side-switch wiper W to and'through the apparatus of the subscribers substation S the side switch wiper W and its first position contact, the middle winding of relay 2, the left-hand winding of relay LR, battery and ground. The right-hand and middle windings of relay 2 are arranged so that the current flowing over them in the circuit just described and in the manner described is not effective in energizing the relay. Relay LR on the other hand is energized in this circuit, and in attracting its armature energizes the release magnet R over a circuit ex tending from ground, the armature and alternate contact of relay LR, the winding of relay R, battery and ground,

It should be noted that the release relay in this system is adapted to be energized throughout the period during which the selector switch SS is in operation, in somewhat the same manner as is disclosed in the patent to F. A. Lundquist, No. 1,252,463, issued January 8, 1918.

The release relay R attracts its armature and extends a ground from its armature and contact, back into the circuit of the line finder switch to hold this switch actuated until the conversation is terminated.

Upon the manipulation of the dial D (assume it to be manipulated in a counter-clockwise drection), the armature of the line re- Patented Feb. 28, 1922.'

lay is caused to vibrate. Upon the first retraction a circuit is established from ground, armature and normal contact of relay LR, lower armature and contact of release relay R, the winding of the primary magnet first position contact and side-switch wiper V winding of escape magnet E, to battery and ground. The escape magnet E and primary magnet PM are energlzed in this c1rcuit, the first remaining energized until the termination of the series of impulses, due to its slow releasing characteristic, and thesecnd causing its armature to vibrate in unison with the armature of the line relay. Durmg this series of impulses, the shaft 4 of the selector switch is caused to rotate step by step, bringing first its two sets of brushes 6 and 6 into association with the terminal banks and t and second, its two sets of brushes b and 6 into association with the banks t and t respectively, in the well-known manner. It will be assumed that two impulses have been sent out in the present instance. Therefore, the sets of brushes h and b will be positioned before the termmal banks 2) and t.

Upon the termination of this series of impulses, the escape magnet Ef retracts its armature, and inv so doing steps the sideswitch wipers W to W, inclusive, into their second positions, whereupon a circut is established from ground, thecontact and armature of escape magnet E, the secondary offnormal contact SON, side-switch wiper W and its second position contact, the winding of relay 3, to battery and ground. Relay 3 is energized in this circuit and attracts-its armature establishing thereby a circuit from ground, the armature and contact of relay 3, lower armature and contact of release relay R, the winding of secondary magnet SM, its armature and contact, second osition contact and the side-switch wiper winding of escape magnet E, to battery and ground. Upon the first vertical step of the shaft 4 under the influence of the ma et SM, the secondary off-normal contact ON is opened, but circuit for the relay 3 is maintained over the test brush of the set 12 from the grounded test terminals of those lines which are at this time busy, .throu h the normal contact and inner right-han armature of relay 2, the wiper W and its second position contact, the winding of relay 3 to battery and ground. When the test brush of the set I) encounters a termnal in the bank t associated with an idle line, the relay 3 will become deenergized and as a consequence will open the circuit for the energization of magnet SM and escape magnet E, whereupon the escape magnet moves the side-switch wipers W to W inclusive into their third positions.

In the third position-of the side switch, line relay LR is disconnected from the line,

and, becoming deenergized, retracts its armature. A circuit is thereupon established from ground in the seized connector switch CS (this ground being established in a manner similar to that described in connection with release relay R) testconductor of the seized trunk, through the; test wiper of the set of brushes 1), the normal contact and innerright-hand armature of the relay 2, thesideswitch wi er W and its third 'osltion contact, win ing of release relay batter to ground, whereby the release relay is maintained energized until the ground is removed from the test conductor of the connector switch at the completion of the conversation.

In the third position the escape magnet is energized over a circuit extending from ground,'armature and normal contact of re, lay LR, third position contact and sideswitch wiper W, windin of esca e magnet E, battery and ground, w ereby t e ground at the contact of this relay is removed from connection with the side-switch wiper W to prevent the energization of the release relay B when 1n the restoration of the switch the secondary off-normal contact SON becomes closed.

The connection is further extended through the manipulation of the dial D,

Assume now that the first manipulation I of the dial switch D had been in a clockwise direction, then as the subscribers finger encountered the member 1 during the setting of the switch, a ground connection will be temporarily made to the line, whereby the balance of the currents flowing through the right hand winding and the middle winding of relay 2 will be disturbed. Specifically, the current throu h the right-hand winding of the relay 2 wifi be reduced to zero, since both sides of the winding are now connected to ground, and the current through the middle winding will be increased, since the right-hand winding of the relay 2 and the right-hand winding of the relay LR are shunted out by the ground connection to the member 1. Relay 2 thereupon attracts its armatures and a locking clrcuit is established from ground, left-hand winding of relay 2, the left-hand armature and contact thereof, the contact member 5, to battery and ground.

Assuming that in its return from set osition the dial D causes the actuation o the contact C twice, then the brush shaft 4 as before will be rotated two steps, and the brush set b will be positioned in association with the terminal bank t. The operation of the various relays within the selective switch in this case is the same as that just described, the only difierence being that the conversational circuit through the three right-hand armatures of the relay 2 is now transferred from brush set I) to brush set I). At the end of the secondary movement of the selector switch, a trunk leading to the connector switch CS will be seized and the connection further extended to substation S 1 Upon the termination of the conversation the shaft 4 in its return to normal through the projection 6 strikes a lever 7, which in turn momentarily actuates contact member 5, whereby the locking circuit of the relay 2 is opened. In this manner the selector switch SS and all of its moving members return to their normal position.

What is claimed is:

1. In a telephone system, multi-group selective switches, groups and subgroups of telephone lines terminating in said switches, calling devices for controlling said switches, means includedin said calling devices responsive to the manner in which said calling devices are set for transmitting an impulse over said lines, means responsive to the setting of said calling devices for setting said switches in relation to a particular group of said lines, and a differentially wound relay responsive to said first means for setting said switches in relation to a particular subgroup of said lines within said selected group of lines.

2. In a telephone system, a selective switch comprising sets of terminals arranged in groups and subgroups, sets of brushes arranged in operative relation with said terminals, a primary magnet for selecting a particular group of said terminals, a differentially wound relay differently responsive to means for setting said switch for selecting a particular subgroup of terminals of said selective group, and a secondary magnet for selecting a particular set of terminals in said selected subgroup.

3. In a telephone system, a selective switch comprising sets of terminals arranged in groups and subgroups and sets of brushes arranged in operative relation with said terminals, telephone lines connected to said sets of terminals, calling devices associated with said lines at the distant end thereof, a

source of current, means for causing said current to flow in equal volume over both sides of said lines, a primary magnet re sponsive to the intermittent flow of said current for setting said switch in association with a group of said terminals, means included in said calling devices for unbalancing the flow of current in said line, means responsive to the unbalanced flow of said current for setting said switch in association with a particular subgroup of said lines in said selected group, and means for setting said switch in association with a particular set of terminals in said selected subgroup of said selected group.

4. In a telephone system groups and subgroups of telephone lines, selective switches for interconnecting said lines, impulse transmitters for controlling said switches, means included in said transmitters responsive to the different manner in which said transmitters are set for differently affecting said lines, means included in said switches responsive to the actuation of said impulse transmitters for selecting groups of said lines and lines in said groups, and differentially wound relays included in said switches differently responsive to the different manner of setting of said impulse transmitters for selecting sub-groups of said selected groups.

5. In a telephone system, telephone lines, each equipped with a sender means included in said sender responsive to the different manner in which said sender is set for differently affecting said lines, divided into groups and sub-groups, an automatic switch for extending a line to any one of said lines in said sub-groups, a differential relay differently responsive to the different manner of setting of said senders for selecting one of said groups, means responsive to the actuation of said senders for selecting a sub-group in said selected group, and means for selecting a line in said selected subgroup.

In witness whereof, we hereunto subscribe our names this 13th day of July, A. I). 1917.

HENRY P. CLAUSEN. CHARLES L. GOODRUM. 

